Troubleshooting help

[dirttorpedo]

Went for a ride this morning. Was powering to the top of a big hill and I lost power. I wasn't hitting it particularly hard because it's muddy where I'm riding. And I don't believe I smoke the motor I wasn't anywhere near my thermal cut offs. But I haven't been able to get any response from the motor under power. When I walk or pedal there's a lot of intermittent resistance. It feels like a spin catch spin catch spin catch with the resistance being every couple inches. It was a rough 7 and 1/2 mile walk home.

I'm running a crystalyte 4065 with a powervelocity controller and a cycle analyst. I've been running this setup for about a year now. I'm showing accurate speed on the CA, so (fingers crossed) I think the Halls are fine. I've also checked the connections coming out if my controller with a multimeter and have verified that the controller probably isn't the issue.

So my plan is to test the halls for voltage using the spin method. And then open up my motor to see if wires may have been severed. I had to do some rerouting or earlier this weekend because I had to replace a tube in tire. I suspect maybe I strapped the cables down to tighten one of them got pulled.

What do you guys think? Would that cause the type of issue I'm having?

 

[E-HP]

I received help on this forum two weeks ago when my motor developed a problem after I removed my wheel to convert to tubeless. I did some work on the phase and hall wires to make it easier the next time I need to remove the wheel. My problem turned out to be a loose connection on one of the phase wires. As one member mentioned, the big clue what that it happened after doing some work on the bike. Fortunately I didn't start disassembling the motor or controller, making the fix a lot easier.
https://endless-sphere.com/forums/viewtopic.php?f=2&t=97742

EDIT: One symptom that I noticed is that although the bike wouldn't respond to throttle, If I pushed wheel just a bit while holding the throttle on full, the wheel would abruptly start spinning. Watch your fingers if you try that. i had that weird resistance thing too, but fortunately it was downhill to my house.

 

[Hwy89]

Physically inspect the phase wires between where they exit the hub and where they are attached to the frame.

 

[dogman dan]

Sounds like shorted phase wires, or you popped the controller. if the resistance vanishes when you unplug the wires from motor to controller, you definitely blew the controller, and the short is in the controller, or the wires to it. You say the controller checks out, but if that resistance vanishes when you unplug, it is in the controller.

if it does not vanish, then you likely melted the motor, unless you find the short in the wires.


If its intermittent power, then its the bad contact problem, or a blown hall. if you popped the controller or melted the motor, its a LOT of resistance.

 

[Volt_Ampere]

Yes - most likely a controller failure.

 

[dirttorpedo]

So a couple of things. I had time to take the motor apart and check my wiring and I haven't found any shorts anywhere. the motor is surprisingly clean inside with the exception of the ferrofluid I was running. I also tested the halls and they all checked out okay. I had time to hook up an old controller my mini-e, running sensorless it did fine but haven't had time to test it with the Halls hooked up. Also the resistance does disappear when I unplug the Halls and phase wires.

So I tend to believe it is a controller issue. Now I'm wondering what that issue is and if it's repairable. Any suggestions

 

[Volt_Ampere]

Controller failures usually involve blown MOSFETs and / or blown caps. Often, you can rebuild it if you can check and replace the mosfets. A shorted mosfet will give you some of the behavior you were having because a motor phase can be shorted to another one through the damaged mosfet.

 

[dirttorpedo]

I was actually thinking FETS but I wasn't sure. I guess my next step is to wire up my backup controller and take this baby apart.

Thanks everyone. Dogman in particular I'm a big fan of the knowledge you spread on the Sphere.

 

[dogman dan]

99.9%, the controller blew a fet. this fet is now shorting the phase wires. Don't take the motor apart. its the controller, or a wire to it, 1000%

 

[dirttorpedo]

Doh! Taking the motor apart was actually one of the first things I did after checking my wiring. I mostly assumed the motor was the issue because I did something stupid when this motor was new and ended up severing a couple of wires. I thought maybe my rewiring job was to blame. Honestly I had FETs on the brain almost from the beginning, but I was babying the bike so I didn't think I was pushing it hard enough for something like that. Taking the motor apart wasn't that big a deal because I've taken these motors apart a few times now. The only issue I had was I wasted some time.

On the plus side now I get to the experience of repairing a blown FET if I decide to do it myself. And thanks to you I have a better grasp on diagnosing controller issues in the future. Thanks Dogman you're my hero!